This invention relates to induction systems for internal combustion engines and more particularly to induction systems for fuel injection equipped internal combustion engines.
The present invention has as its object to improve the combustion in internal combustion engines, and to obtain induction means of high practicability wherein high speed auxiliary intake air is introduced into a combustion chamber from an auxiliary induction passage of relatively small cross-section area opening into a portion of the induction means which is near to an intake valve of a combustion chamber in order to produce in the combustion chamber a high speed eddy current (sometimes called "turbulence"), thereby to increase the flame propagation speed and to stabilize the flame propagation.
In general, the concept of improving combustion in an internal combustion engine by introducing auxiliary intake air into the combustion chamber via an auxiliary induction passage is wellknown. For example, reference is made to U.S. Pat. Nos. 2,968,297 and 3,688,752. However, the construction of the induction means of U.S. Pat. No. 3,968,297 wherein an induction passage and an auxiliary induction passage are provided with a carburetor, respectively, is complicated. In the induction means of the U.S. Pat. No. 3,688,752, wherein only a main intake passage is provided with a carburetor having an auxiliary intake passage provided with no fuel supplying means, the gaseous mixture is diluted with auxiliary intake air, and as a result it is difficult to control the air fuel ratio so that the improving effect on combustion can possibly be offset.